#include<stdio.h>
int main()
{
	int arr[] = {1,2,3,4,5,6,7,8,9,10};
	int k;
	scanf("%d",&k);
	int size = sizeof(arr)/sizeof(arr[0]);//其求数组的个数 
	int left = 0 ;
	int right = size-1;
	while(left<=right)
	{
	int mid = (left+right)/2;//设定中间值 
	if(arr[mid] > k)//判断中间值与该值的大小，若大于该值，则右边的变为中间值减一 
		right = mid - 1;
	else if(arr[mid] < k)
		left = mid + 1;
	else
	{
	printf("该数是%d",arr[mid]);
	break;//跳出循环 
	}
	}
    if(left>right)
    printf("没找到");
	return 0;
}
